...INTERRUPTIBLE AND UNINTERRUPTIBLE AC POWER BACK-UP SYSTEMS INTRODUCTION Fermilab utilizes a variety of emergency AC power systems to provide back-up power to critical loads in the event of power outages. Larger such systems are gas or diesel powered motor-generators. This chapter does not specifically cover these larger systems. Smaller systems are normally powered by the AC electrical distribution system and employ DC batteries for energy storage of sufficient capacity to back-up the protected load for a specific time period. A first version of the smaller type tolerates an interruption of power to the load and is commonly known as an Interruptible Power Supply (IPS). The IPS type system is typically used for emergency egress lighting. The requirements for testing, documenting and repairing emergency egress lighting are specifically addressed in FESHM Chapter 6011 - “PERIODIC TESTING OF EMERGENCY LIGHTS’. The more common version of the emergency power back-up system is the Uninterruptible Power Supply (UPS) which provides continuous uninterrupted AC power to selected loads. The UPS finds use in backing up computer related systems, critical loads (such as the Comm Center), and also emergency egress lighting systems. The voltage output of IPS and UPS systems are typically 120 or 277 VAC. The ampacity of these systems, rated in KVA, and time of being able to provide emergency power vary from system to system. Both the IPS and UPS type systems employ Direct Current (DC)...
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...The main reason The Burj Dubai tower works and allows its occupants to be comfortable lies in its structural design to deal with the main problems such as the wind load, the physical strength of the building and of course the elevator design needed for such a large structure. The Burj Dubai, situated in Dubai, will soon be the tallest building in the world, bypassing the previous record holder, the Taipei 101 by almost 290 metres giving it an astonishing 800 metre height. With over 2700 feet, designing and constructing such a vast building has given significant challenges to engineers and designers alike. Since the building can hold up to 35,000 people at once, it is essential that it is strong, comfortable and able to move people up and down it at a steady rate. This essay will explore how the designers and engineers went about solving these issues. One of the key problems the engineers had to overcome was effect of the wind load and how it would affect the building motions due to the extraordinary height of the tower. Wind load is something that must be taken into account for all buildings, but obviously the wind velocity increases the higher you go and since the structure is over 800 metres tall, there is guaranteed to be a large wind force acting on the building. Three different engineering firms: Skidmore, Owings and Merrill who were all working on the project, hired the RWDI (Rowan Williams Davies & Irwin Inc.) a wind and environmental engineering firm to conduct wind studies...
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...E_1/E_2 =a DC test DC voltage is applied to the stator windings and since the current is dc there will be no induced voltage in the rotor and due to that there will be no induced current, furthermore, the motor reactance is also be zero at direct current, therefore, the only resistance that limits the current is the stator resistance and this resistance can be easily determined. To perform the test, the current of the stator can be adjusted to the rated value and the voltages can be measured and with these the input power at no load and the stator copper loss can be computed and the rotational loss can be computed using the input power and the stator copper losses. The circuit of the DC test is shown below. Minimizing the Errors To minimize the result errors the readings can be taken several times and the average value can be taken to compute the final calculations, therefore, this will ensure that the errors that persist within the measuring equipment and handling errors will be neglected the values will be more...
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...materials when subjected to a constant load or stress’’ (Callister 2011, p.265). The aim of this experiment is to find the creep rate of a rubber in tension. Rubbers are classified as elastomers, elastomers are polymers which have a high degree of crosslinking and it is this crosslinking that allows elastomers to return to their original shape after deformation. Elastomers exhibit viscoelastic behaviour; viscoelastic materials have both viscous and elastic characteristics when undergoing deformation. When a load is applied to a viscoelastic material the deformation is time dependent under constant temperature, this means that the strain increases with time. Figure 1: The creep strain behaviour of a viscoelastic material under constant stress. The strain increases with time while stress remains constant. As the load is applied the strain increases instantaneously, this is the elastic behaviour of the material. In the recovery stage the strain does not return to zero even after a considerable amount of time, this illustrates the viscous property of the material. [Diagram] At: http://dspace.jorum.ac.uk/xmlui/bitstream/handle/10949/1033/Items/T838_1_section23.html (Accessed on 25/10/2014) A typical creep test involves subjecting a specimen to a constant load or stress while keeping the temperature constant. Procedure Figure 2: An illustration of the experimental set-up. Figure 2: An illustration of the experimental set-up. The experimental set up is detailed in figure 2 below. The...
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...University to characterize design fires for clothing stores. The work includes a survey of clothing stores to determine fire load and type of combustibles and medium-scale testing of fuel packages designed to represent the fire loads and type of combustibles in these stores. The experiments are conducted in collaboration with the National Research Council of Canada (NRC)’s Fire Research Program using NRC’s full-scale facilities. Fourteen different clothing stores were surveyed and the data collected were analyzed to determine the total fire load (MJ) in each of the stores, the fire load density (MJ/m2), and the contribution of different combustible materials to the total fire load. The survey was conducted in 2003 in the Canadian cities of Ottawa and Gatineau. The analysis of the survey data indicated that three different fuel packages should be used to represent clothing stores. One package is used to represent clothing stores with small floor area, the second to represent stores with wood as the major combustible, and the third to represent stores with cloth as the major combustible. The results from the tests show that clothing stores that have wood as the main combustible have almost the same burning characteristics (HRR, gas temperatures and concentrations, and heat fluxes) as small size clothing stores with similar burning trends during the test. However, the test with clothing stores that have cloth as the main combustible produced twice the max HRR, a 50% increase in gas...
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...The most famous road test is the ASSHO Road Test which was conducted between 1956 and 1958 in Ottawa, Illinois. The test resulted in the development of the AASHO Design Procedure. The aim of the AASHO Road Test was to establish the relationships between pavement performance, pavement thickness and traffic loading for both flexible and rigid pavements. The test consisted of six two-lane loops (Figure 2). The first loop was not subject any traffic loading but was used investigate the climatic, environmental and subgrade effects. However, the investigations were never carried out. The remaining five loops were subjected to frequent loading by vehicle of varying load types and weight (Figure 3). The layer thickness within each loop was varied in order to establish the relationships between pavement thickness and traffic...
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...2100 100 100 100 115 115 115 140 140 140 150 150 150 165 165 165 190 190 190 2188 2270 46 245 245 245 2598 2598 0 C Overall pipe diam D Overall socket diam E Projection of socket F Effective length G Overall pipe length H Circumference on centre line I Approx weight/pipe in kgs 1100 1280 90 50 1490 1658 1838 1640 1800 1980 80 80 80 2500 2640 5230 5200 4 10 2500 2500 2640 2640 4210 4710 3660 4300 6 15 5 12.5 1100 1280 1380 2500 2500 2500 2620 2620 2620 2655 3142 3660 1640 2100 2650 13 32.5 10 25 8 20 2500 2500 2500 2500 2500 2600 2600 2600 2600 2620 1373 1618 1869 2158 2394 550 38 95 680 30 75 850 25 62.5 1150 1425 18 45 15 37.5 2500 2500 2645 2645 6250 7360 7400 10500 3 7.5 2 5 J Approx no off pipes/21 ton load K No of meters /21 ton load Length varies Length varies Effective Length Effective Length BUTT END SPIGOT BUTT END SOCKET ROCKER PIPE DOUBLE SPIGOT Butt End or square end pipes can be cut on site or supplied if requested. Rocker pipes are as full length pipes except length. Made only to order. Rocker...
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...of the Internet in Online transaction processing (OLTP) and E-commerce applications which use databases. This evolution gave birth to an enduring need for high throughput, good response time, excellent data consistency and concurrency control. This paper evaluates SQL server 2000 and Oracle 9i with respect to performance and scalability. Initial performance tests showed that at low to medium workload both database systems behaved in a similar fashion in terms of throughput and response time. At high load however Oracle 9i emerged victorious in both cases. market and use of the Internet in databases. The first point has lead to competition between commercial and open source database vendors while the second has resulted in a need for high performance database systems. This whole controversy has in the past lead database vendors to employ numerous tricks in bid to improve the processing speed of their systems during benchmarking and thus falsely prove that their databases products are superior to other competitors. Some of their tricks include using high-speed CPUs and clusters, caching up data rows and storing SQL execution plans into RAM prior to testing thus bypassing disk I/O access and tremendously increasing performance (Burleson D, 2002).AS a result the author seeks to provide an independent third voice that will aid DBA in decision making. 1. Introduction This project explores and evaluates...
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...CONCLUSION | 18 | 9 | REFERENCES | 19 | 10 | APPENDIX | 20 | INTRODUCTION Theory This test is performed to determine the consolidation – drained shear strength of a sandy to silty soil. This shear strength is one of the most important engineering properties of a soil, because it is required whenever a structure is depended on a soil shearing resistance. The shear strength is needed for engineering situation such as determining the stability of slopes or cut, finding the bearing capacity for foundation and calculated the pressure exerted by a soil retaining wall. Significance The direct shear stress is a strain – controlled test: the rate at which the soil will be strained is controlled. A specimen of soil will be placed into a shear box, and consolidated under an applied normal load. The shear box is made of two separate halves, an upper and lower. After the application of the normal load, these two halves of box will be moved relative to one another, shearing the soil specimen on the plane that is separation of the two halves. The direct shear test imposes stress condition on the soil that force the failure plane occur at a predetermined location ( on the plane that separates the two halve of the box). One this plane there two force (or stresses) acting – a normal stress, due to an applied vertical load Pᵥ and a shearing stress, due to the applied horizontal load Pᶮ. These stresses are simply computed as : Óᵑ=Pᵥ /A T=Pᵑ/A Where A is the normal area of the...
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...Availability and cost of raw materials * Manufacturing costs * Transportation * Placing * Maintenance * 1.2 Mechanical Properties * Loading conditions * Static load – A sustained loading of the structure over a period of time * Dynamic load – A load that generates a shock or vibration in the structure (periodic – repeats itself with time, random- load pattern never repeats, or transient- impulse load applied over short interval) * Dead load- Static load, always applied (weight of the structure) * Live load- Dynamic loads, (people in a building or movable objects) * Stress-Strain Relations * Stress : σ=FA (psi, ksi, kPa, MPa, GPa) * Strain: ε=Change in LengthOriginal Length (%, in/in, mm/mm) * Elastic behavior * Elasticity- instantaneous response (deformation to load) and must return to its original shape when the load is removed. Stretches the bonds between atoms-doesn’t change arrangement of atoms * Young’s Modulus (Modulus of Elasticity)- Slope of the linear portion of the stress-strain curve E=σε * Poisson’s ratio- Ratio of the lateral strain to the axial strain (must be between 0.0(compressible material)-0.5(does not change volume when load applied)) Usually between 0.1 and 0.45 ν=-εlεa * Generalized Hooke’s Law * εx=σx-ν(σy+σz)E * εy=σy-ν(σz+σx)E * εz=σz-ν(σx+σy)E * Tangent Modulus-...
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...SERVICE SPECIFICATION DNVGL-SE-0074 Edition December 2014 Type and component certification of wind turbines according to IEC 61400-22 The electronic pdf version of this document found through http://www.dnvgl.com is the officially binding version. The documents are available free of charge in PDF format. DNV GL AS FOREWORD DNV GL service specifications contain procedural requirements for obtaining and retaining certificates and other conformity statements to the objects, personnel, organisations and/or operations in question. © DNV GL AS Any comments may be sent by e-mail to rules@dnvgl.com This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document, and is believed to reflect the best of contemporary technology. The use of this document by others than DNV GL is at the user's sole risk. DNV GL does not accept any liability or responsibility for loss or damages resulting from any use of this document. Changes – current CHANGES – CURRENT General This service specification supersedes and replaces the January 2014 edition of DNV-DSS-904. Service specification DNVGL-SE-0074 – Edition December 2014 DNV GL AS Page 3 CHANGES – CURRENT .................................................................................................. 3 Sec.1 Introduction .....................................................................................................
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...G.A.N BRIGHT REPORT PRESENTATION 1. Title 2. Aim 3. Apparatus/Equipments 4. Procedure/Method 5. Theory/Results 6. Safety Precaution 7. Conclusion N/B: Safety Precaution must be minimum of four PART 1 SYNCHRONOUS MACHINE 1.1 INTRODUCTION A synchronous machine is an a.c machine in which the rotor moves at a speed which bears a constant relationship to the frequency of currents, in the armature winding. A synchronous machine is one of the important type of electric machines. Large a.c networks operating at constant frequency of 50Hz rely almost exclusively on synchronous generators, also called the alternators, for the supply of electrical energy. Private, stand-by and peak load plants with diesel or gas-turbine prime movers also have synchronous generators. Synchronous motors provide constant speed industrial drives with the possibility of power factor correction. Synchronous machine are generally constructed in larger sizes. Small size alternators are not economical. The modern trend is to build alternators of very large size capable of generating 500MVA or even more. The synchronous motor is rarely built in small sizes owing to superior performance characteristics and economical construction of induction motors. 1.2 OPERATING PRINCIPLE The operating principle of a synchronous machine is fundamentally the same as that of a d.c machine, but, unlike the latter, in the synchronous machine there is no need...
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...SHEET 1 OF 6 REVISION 03 QP-010011-10 TRACE CODE 1 DOC SAMPLE CAMERON Y/N SIZE INSPECTION (2) (4) - QUALITY PLAN DESCRIPTION: RISER, TELESCOPING JOINT, RISER ADAPTER, RISER RUNNING TOOL ASSEMBLIES AND SUBASSEMBLIES, AND SPIDERS AND GIMBALS, API 16F INSPECTION / TEST ACTIVITY SURVEILLANCE DEFINITIONS STANDARD (1) PROCEDURE AND/OR ACCEPTANCE CRITERIA HOLD CAMERON REQUIREMENT ACTIVITY THAT REQUIRES ONE WORKING DAY ADVANCE NOTIFICATION. WORK SHALL NOT PROCEED BEYOND THIS POINT WITHOUT WRITTEN CONFIRMATION OF WAIVER. WITNESS ACTIVITY THAT REQUIRES ONE WORKING DAY ADVANCE NOTIFICATION. WORK MAY PROCEED ON SCHEDULE SHOULD THE REPRESENTATIVES FAIL TO SHOW FOR THE ACTIVITY. WAIVER OF NOTIFICATION REQUIREMENTS SHALL BE IN WRITING. MONITOR ACCESS SHALL BE PROVIDED TO ALLOW SURVEILLANCE ON SITE AND AT SUB-SUPPLIERS. MONITORING ACTIVITIES ARE NOT RESTRICTED TO SPECIFICALLY IDENTIFIED MONITOR POINTS AND WILL NOT BE SUBJECT TO ANY FORMAL NOTIFICATION, THOUGH MANUFACTURING PERSONNEL ARE EXPECTED TO SHARE PLANNING AND SCHEDULING INFORMATION. REVIEW APPROPRIATE RECORDS OF THE ACTIVITY SHALL BE PROVIDED FOR REVIEW. WHERE PRACTICAL, REVIEW OF RECORDS SHALL TAKE PLACE PROGRESSIVELY THROUGHOUT THE MANUFACTURE AND TEST PROCESS. CAMERON SOURCE INSPECTION ACTIVITY THAT REQUIRES PROVIDING ONE WORKING DAY ADVANCE NOTIFICATION FOR INSPECTION OR WITNESS OF INSPECTION BY CAMERON REPRESENTATIVE. ACTIVITIES WAIVED BY CAMERON SHALL BE IN WRITING. PREMANUFACTURING MEETING CAMERON A PRE-MANUFACTURING...
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...THE RELATIONSHIP BETWEEN SUBJECT LOADS AND STUDY HABITS AMONG THE ACCOUNTANCY STUDENTS OF HOLY CROSS OF DAVAO COLLEGE A Research Paper Presented to Mrs. Nelia B. Aga by Manalo, Ma. Reignsel Angelica V. Copreros, Ariela September 2015 The Relationship between Subject Loads and Study Habits Among the Accountancy Students Of Holy Cross of Davao College _________________ A Research Paper Presented to Mrs. Nelia B. Aga _________________ In Partial Fulfillment Of the Requirements for English 103 __________________ by Manalo, Ma. Reignsel Angelica V. Copreros, Ariela B. September 2015 ii HOLY CROSS OF DAVAO COLLEGE STA. ANA AVENUE, DAVAO CITY Approval Sheet This research entitled “The Relationship between Subject Loads and Study Habits Among the Accountancy Students of Holy Cross of Davao College”, prepared and submitted by Ma. Reignsel Angelica V. Manado and ArielaCopreros, in partial fulfillment on English 103, Methods of Research and Technical Writing, has been examined and recommended for acceptance and approval. Mrs. Nelia B. Aga Instructor ii Acknowledgement The researchers would like to thank from the bottom of their heart to the people who became part of the conduction of this study. And also who are there to support financial or even emotional so that this study becomes successful. First and for most, the researchers would like to express their sincere thanks to our Almighty God because He...
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...Software Testing What is testing? Testing is the process of evaluating a system or its component(s) with the intent to find that whether it satisfies the specified requirements or not. This activity results in the actual, expected and difference between their results. In simple words testing is executing a system in order to identify any gaps, errors or missing requirements in contrary to the actual desire or requirements. Who does testing? It depends on the process and the associated stakeholders of the project(s). In the IT industry, large companies have a team with responsibilities to evaluate the developed software in the context of the given requirements. Moreover, developers also conduct testing which is called Unit Testing. In most cases, following professionals are involved in testing of a system within their respective capacities: Software Tester Software Developer Project Lead/Manager End User When to Start Testing? An early start to testing reduces the cost, time to rework and error free software that is delivered to the client. However in Software Development Life Cycle (SDLC) testing can be started from the Requirements Gathering phase and lasts till the deployment of the software. However it also depends on the development model that is being used. For example in Water fall model formal testing is conducted in the Testing phase, but in incremental model, testing is performed at the end of every increment/iteration and at the end the whole application is tested. Testing...
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